U.S. patent application number 15/185693 was filed with the patent office on 2016-10-13 for magnetic memory devices having perpendicular magnetic tunnel structures therein.
The applicant listed for this patent is Sangyong Kim, Whankyun Kim, Sechung Oh. Invention is credited to Sangyong Kim, Whankyun Kim, Sechung Oh.
Application Number | 20160301000 15/185693 |
Document ID | / |
Family ID | 53172450 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160301000 |
Kind Code |
A1 |
Kim; Sangyong ; et
al. |
October 13, 2016 |
Magnetic Memory Devices Having Perpendicular Magnetic Tunnel
Structures Therein
Abstract
Magnetic memory cells include a magnetic tunnel junction and a
first electrode, which is electrically coupled to the magnetic
tunnel junction by a first conductive structure. This conductive
structure includes a blocking layer and a seed layer, which extends
between the blocking layer and the magnetic tunnel junction. The
blocking layer is formed as an amorphous metal compound. In some of
the embodiments, the blocking layer is a thermally treated layer
and an amorphous state of the blocking layer is maintained during
and post thermal treatment.
Inventors: |
Kim; Sangyong; (Suwon-si,
KR) ; Kim; Whankyun; (Seoul, KR) ; Oh;
Sechung; (Yongin-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kim; Sangyong
Kim; Whankyun
Oh; Sechung |
Suwon-si
Seoul
Yongin-si |
|
KR
KR
KR |
|
|
Family ID: |
53172450 |
Appl. No.: |
15/185693 |
Filed: |
June 17, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14473334 |
Aug 29, 2014 |
9397286 |
|
|
15185693 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11C 11/161 20130101;
H01L 43/08 20130101; H01L 43/02 20130101 |
International
Class: |
H01L 43/02 20060101
H01L043/02; H01L 43/08 20060101 H01L043/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 18, 2013 |
KR |
10-2013-0140135 |
Claims
1. A magnetic memory device, comprising: first and second magnetic
structures comprising a tunnel barrier layer therebetween; an
electrode separated from the tunnel barrier layer by the first
magnetic structure; and a blocking layer between the first magnetic
structure and the electrode, the blocking layer comprising an
amorphous compound.
2. The memory device of claim 1, wherein an amorphous state of the
blocking layer is maintained post thermal treatment.
3. The memory device of claim 1, wherein the blocking layer
comprises a non-metal element.
4. The memory device of claim 1, wherein the blocking layer
comprises a non-magnetic metal element.
5. The memory device of claim 1, wherein the blocking layer
comprises a magnetic element.
6. The memory device of claim 3, wherein the non-metal element
comprises boron, nitrogen, or combinations thereof.
7. The memory device of claim 4, wherein the non-magnetic metal
element comprises tantalum (Ta), tungsten (W), niobium (Nb),
titanium (Ti), chromium (Cr), zirconium (Zr), hafnium (Hf),
molybdenum (Mo), aluminum (Al), magnesium (Mg), ruthenium (Ru),
vanadium (V), or combinations thereof.
8. The memory device of claim 5, wherein the magnetic element
comprises cobalt, iron, nickel, or combinations thereof.
9. The memory device of claim 1, wherein the blocking layer
comprises cobalt-iron-boron-tantalum (CoFeBTa).
10. The memory device of claim 1, wherein the blocking layer is a
non-magnetic layer.
11. The memory device of claim 10, wherein the blocking layer
comprises a non-magnetic metal element.
12. The memory device of claim 11, wherein the non-magnetic metal
element comprises tantalum.
13. The memory device of claim 1, wherein the blocking layer
comprises tantalum nitride (TaN).
14. The memory device of claim 4, wherein a content ratio of the
non-magnetic metal element in the blocking layer is in a range from
about 15 wt % to about 50 wt %.
15. The memory device of claim 1, wherein the blocking layer has a
thickness in a range from about 0.1 .ANG. to about 20 .ANG..
16. The memory device of claim 1, further comprising a seed layer
between the first magnetic structure and the blocking layer; and
wherein the blocking layer contacts the seed layer.
17. The memory device of claim 16, wherein the first magnetic
structure comprises: an exchange coupling layer between the tunnel
barrier layer and the seed layer; a first magnetic layer having a
fixed magnetization direction, between the tunnel barrier layer and
the exchange coupling layer; and a second magnetic layer having a
fixed magnetization direction, between the exchange coupling layer
and the seed layer.
18. The memory device of claim 16, wherein the first magnetic
structure comprises a magnetic layer having a changeable
magnetization direction, between the tunnel barrier layer and the
seed layer.
19. The memory device of claim 6, wherein the electrode is a first
electrode and the blocking layer is a first blocking layer; and
wherein the memory device further comprises: a second electrode
spaced apart from the tunnel barrier layer with the second magnetic
structure therebetween; and a second blocking layer between the
second magnetic structure and the second electrode, said second
blocking layer comprising an amorphous compound.
20. The memory device of claim 19, further comprising: a seed layer
between the first magnetic structure and the first blocking layer;
and a capping layer between the second magnetic structure and the
second blocking layer; and wherein the first blocking layer is in
contact with a surface of the seed layer, and the second blocking
layer is in contact with one surface of the capping layer.
Description
REFERENCE TO PRIORITY APPLICATION
[0001] The present application is a continuation application of and
claims priority from U.S. patent application Ser. No. 14/473,334
filed on Aug. 29, 2014, which claims priority under 35 U.S.C.
.sctn.119 to Korean Patent Application No. 10-2013-0140135, filed
Nov. 18, 2013 in the Korean Intellectual Property Office, the
disclosures of which are hereby incorporated herein by reference in
their entirety.
BACKGROUND
[0002] The inventive concepts relate to magnetic memory devices
and, more particularly, to magnetic memory devices having
perpendicular magnetic tunnel junctions therein.
[0003] High speed and/or low voltage semiconductor memory devices
have been demanded with the development of high speed and/or low
power consumption electronic devices including semiconductor memory
devices. To satisfy these demands, a magnetic memory device has
been suggested. The magnetic memory device has high speed and/or
non-volatile characteristics, so as to be spotlighted as a next
generation semiconductor memory device.
[0004] Generally, the magnetic memory device may include a magnetic
tunnel junction (MTJ) pattern. The MTJ pattern may include two
magnetic layers and an insulating layer disposed therebetween. A
resistance value of the MTJ pattern may be changed depending on
magnetization directions of the two magnetic layers. For example,
if the magnetization directions of the two magnetic layers are
anti-parallel to each other, the MTJ pattern may have a high
resistance value. If the magnetization directions of the two
magnetic layers are parallel to each other, the MTJ pattern may
have a low resistance value. Logical data may be written/read using
a difference between the high and low resistance values of the MTJ
pattern.
[0005] High integrated and/or low power consumption magnetic memory
devices have been increasingly demanded with the development of an
electronic industry. Thus, various researches are being conducted
for magnetic memory devices capable of satisfying the demands.
SUMMARY
[0006] Magnetic memory devices according to embodiments of the
invention can include an array of magnetic memory cells
electrically connected to respective word and bit lines. According
to some of these embodiments of the invention, a magnetic memory
cell can include a magnetic tunnel junction (MTJ) and a first
electrode electrically coupled to the magnetic tunnel junction by a
first conductive structure. This first conductive structure may
include a blocking layer and a seed layer, which extends between
the blocking layer and the magnetic tunnel junction. The blocking
layer may be formed as or at least include an amorphous metal
compound material.
[0007] In some embodiments of the invention, the blocking layer is
deposited, patterned and thermally treated. Moreover, an amorphous
state of the blocking layer is preferably maintained during and
post thermal treatment. The blocking layer may include
ferromagnetic, non-metal and non-magnetic metal elements, for
example. The non-metal element may be selected from a group
consisting of boron and nitrogen and combinations thereof. A
content ratio of the non-magnetic metal element in the blocking
layer may be in a range from about 15 wt % to about 50 wt %.
[0008] A magnetic memory device according to additional embodiments
of the invention may include first and second perpendicular
magnetic structures (MS1, MS2) having a tunnel barrier layer
therebetween. An electrode is provided, which is separated from the
tunnel barrier layer by the first perpendicular magnetic structure.
A blocking layer is provided, which extends between the first
perpendicular magnetic structure and the electrode. The blocking
layer includes an amorphous metal compound. This blocking layer is
typically a thermally treated layer, and an amorphous state of the
blocking layer is maintained during the thermal treatment after the
thermal treatment. The blocking layer may be formed from
ferromagnetic, non-metal and non-magnetic metal elements.
[0009] In some embodiments of the invention, the ferromagnetic
element is selected from a group consisting of cobalt, iron and
nickel and combinations thereof, whereas the non-metal element is
selected from a group consisting of boron and nitrogen and
combinations thereof. The non-magnetic metal element may be
selected from a group consisting of tantalum (Ta), tungsten (W),
niobium (Nb), titanium (Ti), chromium (Cr), zirconium (Zr), hafnium
(Hf), molybdenum (Mo), aluminum (Al), magnesium (Mg), ruthenium
(Ru) and vanadium (V) and combinations thereof. For example, the
blocking layer may be formed as a cobalt-iron-boron-tantalum
(CoFeBTa) layer in some embodiments of the invention. In still
further embodiments of the invention, a content ratio of the
non-magnetic metal element in the blocking layer is in a range from
about 15 wt % to about 50 wt %. The blocking layer may be formed to
have a thickness in a range from about 0.1 .ANG. to about 20
.ANG..
[0010] According to still further embodiments of the invention, a
seed layer may be provided, which extends between the first
perpendicular magnetic structure and the blocking layer. The
blocking layer may contact the seed layer. The first perpendicular
magnetic structure may also include: (i) an exchange coupling
layer, which extends between the tunnel barrier layer and the seed
layer; (ii) a first magnetic layer having a fixed magnetization
direction, which extends between the tunnel barrier layer and the
exchange coupling layer; and (iii) a second magnetic layer having a
fixed magnetization direction, which extends between the exchange
coupling layer and the seed layer. In additional embodiments of the
invention, the first perpendicular magnetic structure includes a
magnetic layer having a changeable magnetization direction, which
extends between the tunnel barrier layer and the seed layer.
[0011] According to further embodiments of the invention, the
electrode is a first electrode and the blocking layer is a first
blocking layer, and the memory device further includes: (i) a
second electrode spaced apart from the tunnel barrier layer with
the second perpendicular magnetic structure extending therebetween;
and (ii) a second blocking layer extending between the second
perpendicular magnetic structure and the second electrode. This
second blocking layer may include an amorphous metal compound. This
memory device may also include a seed layer extending between the
first perpendicular magnetic structure and the first blocking layer
and a capping layer extending between the second perpendicular
magnetic structure and the second blocking layer. The first
blocking layer may be in contact with a surface of the seed layer
and the second blocking may be in contact with one surface of the
capping layer.
[0012] A magnetic memory device according to additional embodiments
of the invention may include a magnetic tunnel junction including a
free layer, a pinned layer, and a tunnel barrier between the free
layer and the pinned layer, an electrode on the magnetic tunnel
junction, and a blocking layer between the magnetic tunnel junction
and the electrode. A saturation magnetization value of the blocking
layer is smaller than saturation magnetization values of magnetic
layers constituting the magnetic tunnel junction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The inventive concepts will become more apparent in view of
the attached drawings and accompanying detailed description.
[0014] FIG. 1 is a circuit diagram illustrating a unit memory cell
of a magnetic memory device according to example embodiments of the
inventive concepts;
[0015] FIGS. 2 and 3 are diagrams illustrating magnetic tunnel
junctions according to example embodiments of the inventive
concepts;
[0016] FIG. 4 is a cross-sectional view illustrating a magnetic
memory device according to some embodiments of the inventive
concepts;
[0017] FIG. 5 is a cross-sectional view illustrating a magnetic
memory device according to other embodiments of the inventive
concepts;
[0018] FIG. 6 is a cross-sectional view illustrating a magnetic
memory device according to still other embodiments of the inventive
concepts;
[0019] FIGS. 7 and 8 are cross-sectional views illustrating
examples of a first perpendicular magnetic structure constituting a
portion of a magnetic tunnel junction according to embodiments of
the inventive concepts;
[0020] FIGS. 9 and 10 are cross-sectional views illustrating
examples of a second perpendicular magnetic structure constituting
a portion of a magnetic tunnel junction according to embodiments of
the inventive concepts; and
[0021] FIGS. 11 and 12 are schematic block diagrams illustrating
electronic devices including magnetic memory devices according to
embodiments of the inventive concepts.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] The inventive concepts will now be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments of the inventive concepts are shown. The
advantages and features of the inventive concepts and methods of
achieving them will be apparent from the following exemplary
embodiments that will be described in more detail with reference to
the accompanying drawings. It should be noted, however, that the
inventive concepts are not limited to the following exemplary
embodiments, and may be implemented in various forms. Accordingly,
the exemplary embodiments are provided only to disclose the
inventive concepts and let those skilled in the art know the
category of the inventive concepts. In the drawings, embodiments of
the inventive concepts are not limited to the specific examples
provided herein and may be exaggerated for clarity.
[0023] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to limit the
invention. As used herein, the singular terms "a," "an" and "the"
are intended to include the plural forms as well, unless the
context clearly indicates otherwise. As used herein, the term
"and/or" includes any and all combinations of one or more of the
associated listed items. It will be understood that when an element
is referred to as being "connected" or "coupled" to another
element, it may be directly connected or coupled to the other
element or intervening elements may be present.
[0024] Similarly, it will be understood that when an element such
as a layer, region or substrate is referred to as being "on"
another element, it can be directly on the other element or
intervening elements may be present. In contrast, the term
"directly" means that there are no intervening elements. It will be
further understood that the terms "comprises", "comprising,",
"includes" and/or "including", when used herein, specify the
presence of stated features, integers, steps, operations, elements,
and/or components, but do not preclude the presence or addition of
one or more other features, integers, steps, operations, elements,
components, and/or groups thereof.
[0025] Additionally, the embodiment in the detailed description
will be described with sectional views as ideal exemplary views of
the inventive concepts. Accordingly, shapes of the exemplary views
may be modified according to manufacturing techniques and/or
allowable errors. Therefore, the embodiments of the inventive
concepts are not limited to the specific shape illustrated in the
exemplary views, but may include other shapes that may be created
according to manufacturing processes. Areas exemplified in the
drawings have general properties, and are used to illustrate
specific shapes of elements. Thus, this should not be construed as
limited to the scope of the inventive concepts.
[0026] It will be also understood that although the terms first,
second, third etc. may be used herein to describe various elements,
these elements should not be limited by these terms. These terms
are only used to distinguish one element from another element.
Thus, a first element in some embodiments could be termed a second
element in other embodiments without departing from the teachings
of the present invention. Exemplary embodiments of aspects of the
present inventive concepts explained and illustrated herein include
their complementary counterparts. The same reference numerals or
the same reference designators denote the same elements throughout
the specification.
[0027] Moreover, exemplary embodiments are described herein with
reference to cross-sectional illustrations and/or plane
illustrations that are idealized exemplary illustrations.
Accordingly, variations from the shapes of the illustrations as a
result, for example, of manufacturing techniques and/or tolerances,
are to be expected. Thus, exemplary embodiments should not be
construed as limited to the shapes of regions illustrated herein
but are to include deviations in shapes that result, for example,
from manufacturing. For example, an etching region illustrated as a
rectangle will, typically, have rounded or curved features. Thus,
the regions illustrated in the figures are schematic in nature and
their shapes are not intended to illustrate the actual shape of a
region of a device and are not intended to limit the scope of
example embodiments.
[0028] FIG. 1 is a circuit diagram illustrating a unit memory cell
of a magnetic memory device according to example embodiments of the
inventive concepts. Referring to FIG. 1, a unit memory cell UMC is
disposed between a first interconnection L1 and a second
interconnection L2 crossing each other. The unit memory cell UMC is
connected to the first and second interconnections L1 and L2. The
unit memory cell UMC may include a switching component SW and a
magnetic tunnel junction MTJ. The switching component SW and the
magnetic tunnel junction MTJ may be electrically connected in
series to each other. One of the first and second interconnections
L1 and L2 may be used as a word line, and the other of the first
and second interconnections L1 and L2 may be used as a bit
line.
[0029] The switching component SW may be configured to selectively
control a flow of charges passing through the magnetic tunnel
junction MTJ. For example, the switching component SW may be one of
a diode, a PNP bipolar transistor, an NPN bipolar transistor, an
NMOS field effect transistor, and a PMOS field effect transistor.
If the switching component SW is a three-terminal element such as
the bipolar transistor or the MOS field effect transistor, an
additional interconnection (not shown) may be connected to the
switching component SW.
[0030] The magnetic tunnel junction MTJ may include a first
perpendicular magnetic structure MS1, a second perpendicular
magnetic structure MS2, and a tunnel barrier TBR disposed between
the first and second perpendicular magnetic structures MS1 and MS2.
Each of the first and second perpendicular magnetic structures MS1
and MS2 may include at least one magnetic layer formed of a
magnetic material. In some embodiments, the unit memory cell UMC
may further include a first conductive structure CS1 disposed
between the first perpendicular magnetic structure MS1 and the
switching component SW and a second conductive structure CS2
disposed between the second perpendicular magnetic structure MS2
and the second interconnection L2, as illustrated in FIG. 1.
[0031] FIGS. 2 and 3 are diagrams illustrating magnetic tunnel
junctions according to example embodiments of the inventive
concepts. Referring to FIGS. 2 and 3, a magnetization direction of
one of the magnetic layer of the first perpendicular magnetic
structure MS1 and the magnetic layer of the second perpendicular
magnetic structure MS2 is fixed regardless of an external magnetic
field under a normal usage environment. Hereinafter, the magnetic
layer having this fixed magnetization property is defined as a
pinned layer PNL. A magnetization direction of the other of the
magnetic layers of the first and second perpendicular magnetic
structures MS1 and MS2 may be switched by an applied external
magnetic field or spin transfer torque of electrons in a program
current. Hereinafter, the magnetic layer having this switchable
magnetization property is defined as a free layer FRL. The magnetic
tunnel junction MTJ may include at least one free layer FRL and at
least one pinned layer PNL separated from the at least one free
layer FRL by the tunnel barrier TBR.
[0032] An electrical resistance of the magnetic tunnel junction MTJ
may be dependent on the magnetization directions of the free layer
FRL and the pinned layer PNL. For example, the magnetic tunnel
junction MTJ may have a first electrical resistance when the
magnetization directions of the free layer FRL and the pinned layer
PNL are parallel to each other, and the magnetic tunnel junction
MTJ may have a second electrical resistance greater than the first
electrical resistance when the magnetization directions of the free
layer FRL and the pinned layer PNL are anti-parallel to each other.
As a result, the electrical resistance of the magnetic tunnel
junction MTJ may be controlled by changing the magnetization
direction of the free layer FRL. This may be used as a data storing
principle of the magnetic memory device according to embodiments of
the inventive concepts.
[0033] The first and second perpendicular magnetic structures MS1
and MS2 of the magnetic tunnel junction MTJ may be sequentially
stacked on a substrate 100, as illustrated in FIGS. 2 and 3. In
this case, the magnetic tunnel junction MTJ may be one of two types
according to a relative position between the free layer FRL and the
substrate 100 and/or a formation order of the free layer FRL and
the pinned layer PNL. In some embodiments, the magnetic tunnel
junction MTJ may be a first type magnetic tunnel junction MTJ1 of
which first and second perpendicular magnetic structures MS1 and
MS2 include the pinned layer PNL and the free layer FRL,
respectively, as illustrated in FIG. 2. In other embodiments, the
magnetic tunnel junction MTJ may be a second type magnetic tunnel
junction MTJ2 of which first and second perpendicular magnetic
structures MS1 and MS2 include the free layer FRL and the pinned
layer PNL, respectively, as illustrated in FIG. 3.
[0034] FIG. 4 is a cross-sectional view illustrating a magnetic
memory device according to some embodiments of the inventive
concepts. Referring to FIG. 4, a first dielectric layer 102 may be
disposed on a substrate 100, and a lower contact plug 104 may
penetrate the first dielectric layer 102. A bottom surface of the
lower contact plug 104 may be electrically connected to one
terminal of a switching component. The substrate 100 may include at
least one of materials having a semiconductor property, insulating
materials, a semiconductor covered with an insulating material, and
a conductor covered with an insulating material. In some
embodiments, the substrate 100 may be a silicon wafer. The first
dielectric layer 102 may include an oxide (e.g., silicon oxide), a
nitride (e.g., silicon nitride), and/or an oxynitride (e.g.,
silicon oxynitride). The lower contact plug 104 may include a
conductive material. For example, the lower contact plug 104 may
include at least one of a semiconductor doped with dopants (e.g.,
doped silicon, doped germanium, or doped silicon-germanium), a
metal (e.g., titanium, tantalum, or tungsten), and a conductive
metal nitride (e.g., titanium nitride or tantalum nitride).
[0035] A first conductive structure CS1, a magnetic tunnel junction
MTJ, and a second conductive structure CS2 may be sequentially
stacked on the first dielectric layer 102. The first conductive
structure CS1 may be electrically connected to a top surface of the
lower contact plug 104. The first conductive structure CS1, the
magnetic tunnel junction MTJ, and the second conductive structure
CS2 may have sidewalls aligned with each other.
[0036] The first conductive structure CS1 may include a first
electrode 106 on the first dielectric layer 102, a seed layer 110
on the first electrode 106, and a blocking layer 108 between the
first electrode 106 and the seed layer 110. The magnetic tunnel
junction MTJ may include a first perpendicular magnetic structure
MS1 on the seed layer 110, a second perpendicular magnetic
structure MS2 on the first perpendicular magnetic structure MS1,
and a tunnel barrier TBR between the first and second perpendicular
magnetic structures MS1 and MS2. In more detail, the first
perpendicular magnetic structure MS1 may be disposed between the
seed layer 110 and the tunnel barrier TBR, and the second
perpendicular magnetic structure MS1 may be disposed between the
tunnel barrier TBR and the second conductive structure CS2. The
second conductive structure CS2 may include a second electrode 114
on the second perpendicular magnetic structure MS2, and a capping
layer 112 between the second perpendicular magnetic structure MS2
and the second electrode 114.
[0037] The first electrode 106 may be electrically connected to the
top surface of the lower contact plug 104. The first electrode 106
may include a conductive material having a predetermined crystal
structure. In some embodiments, the first electrode 106 may include
a conductive metal nitride such as titanium nitride and/or tantalum
nitride. The blocking layer 108 may include an amorphous metal
compound. Hereinafter, a metal compound means a material composed
of a metal element and a different element from the metal element.
The blocking layer 108 may be in an amorphous state when the
blocking layer 108 is deposited. Additionally, the amorphous state
of the blocking layer 108 may be maintained after an annealing
process performed after the deposition of the blocking layer
108.
[0038] In a first embodiment, the blocking layer 108 may be a thin
layer including a metal compound composed of a ferromagnetic
element, a non-metal element, and a non-magnetic metal element. The
ferromagnetic element may include at least one of cobalt, iron, and
nickel. The non-metal element may include at least one of boron,
nitrogen, and oxygen. The non-magnetic metal element may include at
least one of tantalum (Ta), tungsten (W), niobium (Nb), titanium
(Ti), chrome (Cr), zirconium (Zr), hafnium (Hf), molybdenum (Mo),
aluminum (Al), magnesium (Mg), ruthenium (Ru), and vanadium (V). In
some embodiments, the blocking layer 108 may include
cobalt-iron-boron-tantalum (CoFeBTa). In this case, a saturation
magnetization (Ms) value of the blocking layer 108 may be smaller
than saturation magnetization values of magnetic layers included in
the magnetic tunnel junction MTJ. In some embodiments, the
saturation magnetization value of the blocking layer 108 may be
about 10 emu/cm.sup.3 or less.
[0039] A content ratio of the non-magnetic metal element in the
blocking layer 108 may be in a range of about 15 wt % to about 50
wt %. If the content ratio of the non-magnetic metal element is
smaller than about 15 wt %, it is difficult to reduce the
saturation magnetization value of the blocking layer 108.
Additionally, the blocking layer 108 may be crystallized by the
annealing process such that it is difficult to maintain the
amorphous state of the blocking layer 108. If the content ratio of
the non-magnetic metal element is greater than about 50 wt %, the
blocking layer 108 may also be crystallized by the annealing
process such that it is difficult to maintain the amorphous state
of the blocking layer 108.
[0040] In a second embodiment, the blocking layer 108 may be a thin
layer including a metal compound composed of a non-magnetic metal
element and an oxygen element. The non-magnetic metal element may
include at least one of tantalum (Ta), tungsten (W), niobium (Nb),
titanium (Ti), chrome (Cr), zirconium (Zr), hafnium (Hf),
molybdenum (Mo), aluminum (Al), magnesium (Mg), ruthenium (Ru), and
vanadium (V). In some embodiments, the blocking layer 108 may
include ruthenium oxide(RuOx). In this case, the blocking layer 108
may be a non-magnetic layer. In other words, a saturation
magnetization value of the blocking layer 108 may be 0 (zero)
emu/cm'. In still other embodiments, the blocking layer 108 may
have a multi-layered structure including one thin layer of the
first embodiment described above and one thin layer of the second
embodiment described above.
[0041] A thickness of the blocking layer 108 may be in a range from
about 0.1 .ANG. to about 20 .ANG.. In some embodiments, even though
the blocking layer 108 is deposited with a thickness of about 20
.ANG. or less, the blocking layer 108 may not be crystallized by
the annealing process but the amorphous state of the blocking layer
108 may be maintained. The blocking layer 108 may have a planarized
top surface U1 by a planarization process which is performed after
the deposition of the blocking layer 108 and before deposition of
the seed layer 110.
[0042] Generally, the first electrode 106 may have a predetermined
crystal structure and may be adjacent to the seed layer 110 with a
metal layer therebetween. The metal layer may be in an amorphous
state during a deposition process but may then be crystallized by
an annealing process performed after the deposition process. Thus,
the crystal structure of the first electrode 106 may be transferred
to the seed layer 110 through the metal layer. The transferred
crystal structure may influence a crystal structure and orientation
of the magnetic tunnel junction MTJ formed using the seed layer 110
as a seed. As a result, a tunnel magnetic resistance (TMR)
characteristic of the magnetic tunnel junction MTJ may be
deteriorated. Additionally, an exchange coupling characteristic
between magnetic layers in the magnetic tunnel junction MTJ may
also be deteriorated.
[0043] According to embodiments of the inventive concepts, the
blocking layer 108 including the amorphous metal compound may not
be crystallized by the annealing process performed after the
deposition of the blocking layer 108 such that the amorphous state
of the blocking layer 108 may be maintained after the annealing
process. Since the blocking layer 108 is disposed between the first
electrode 106 and the seed layer 110, it is possible to prevent the
crystal structure of the first electrode 106 from being transferred
to the seed layer 110 by the annealing process. In other words, it
is possible to prevent the crystal structure of the first electrode
106 from influencing the crystal structure and the orientation of
the magnetic tunnel junction MTJ through the seed layer 110 by the
annealing process. Thus, the TMR characteristic and the exchange
coupling characteristic of the magnetic tunnel junction MTJ may be
improved.
[0044] The seed layer 110 may include a material capable of
promoting crystal growth of the magnetic layers included in the
magnetic tunnel junction MTJ. In some embodiments, the seed layer
110 may include metal atoms constituting a hexagonal close packed
(HCP) lattice. For example, the seed layer 110 may include at least
one of ruthenium (Ru) and titanium (Ti). In other embodiments, the
seed layer 110 may include metal atoms constituting a face-centered
cubic (FCC) lattice. For example, the seed layer 110 may include at
least one of platinum (Pt), palladium (Pd), gold (Au), silver (Ag),
copper (Cu), and aluminum (Al). The seed layer 110 may have a
single layer. Alternatively, the seed layer 110 may include a
plurality of layers having different crystal structures from each
other.
[0045] FIGS. 7 and 8 are cross-sectional views illustrating
examples of a first perpendicular magnetic structure constituting a
portion of a magnetic tunnel junction according to embodiments of
the inventive concepts. Referring to FIG. 7, the first
perpendicular magnetic structure MS1 may include a first pinned
layer 130, a first exchange coupling layer 132 and a second pinned
layer 134 which are sequentially stacked between the seed layer 110
and the tunnel barrier TBR. The first perpendicular magnetic
structure MS1 according to the present embodiment may be a
multi-layered magnetic structure including the pinned layer PNL
included in the first type magnetic tunnel junction MTJ1 described
with reference to FIG. 2.
[0046] In more detail, the first pinned layer 130 may be disposed
between the seed layer 110 and the first exchange coupling layer
132, and the second pinned layer 134 may be disposed between the
first exchange coupling layer 132 and the tunnel barrier TBR. The
first pinned layer 130 may be formed of a magnetic material having
an intrinsic perpendicular magnetization property (hereinafter,
referred to as `a perpendicular magnetic material). Here, the
intrinsic perpendicular magnetization property means that a
magnetic layer has a magnetization direction parallel to a
thickness direction of the magnetic layer when external factors do
not exist. In some embodiments, if the magnetic layer having the
intrinsic perpendicular magnetization property is formed on a
substrate, the magnetization direction of the magnetic layer may be
substantially perpendicular to a top surface of the substrate.
[0047] The intrinsic perpendicular magnetization property of the
first pinned layer 130 may be realized by a single-layered or
multi-layered structure including at least one of perpendicular
magnetic materials including cobalt. In some embodiments, the first
pinned layer 130 may have a single-layered or multi-layered
structure including a cobalt-platinum alloy or a cobalt-platinum
alloy including a composition X. The composition X may include at
least one of boron, ruthenium, chrome, tantalum, and an oxide. In
other embodiments, the first pinned layer 130 may have a
multi-layered structure including cobalt-containing layers and
noble metal layers which are alternately and repeatedly stacked. In
this case, the cobalt-containing layers may be formed of one of
cobalt, cobalt-iron, cobalt-nickel, and cobalt-chrome, and the
noble metal layers may be formed of one of platinum and palladium.
In still other embodiments, the first pinned layer 130 may have a
multi-layered structure including one structure of the some
embodiments described above and one structure of the other
embodiments described above.
[0048] In some embodiments, a thickness of the first pinned layer
130 may be in a range of about 20 .ANG. to about 80 .ANG.. More
particularly, the thickness of the first pinned layer 130 may be in
a range of about 30 .ANG. to about 55 .ANG.. The aforementioned
materials of the first pinned layer 130 were described as examples
of the materials having the intrinsic perpendicular magnetization
property of the first pinned layer 130. However, the inventive
concepts are not limited thereto. In other embodiments, the first
pinned layer 130 may include cobalt-iron-terbium (CoFeTb) including
terbium having a content ratio of about 10% or more,
cobalt-iron-gadolinium (CoFeGd) including gadolinium (Gd) having a
content ratio of about 10% or more, cobalt-rion-dysprosium
(CoFeDy), iron-platinum (FePt) having an L1.sub.0 structure,
iron-palladium (FePd) having the L1.sub.0 structure,
cobalt-palladium (CoPd) having the L1.sub.0 structure,
cobalt-platinum (CoPt) having an L1.sub.0 or L1.sub.1 structure,
cobalt-platinum (CoPt) having a hexagonal close packed (HCP)
structure, or any alloy including at least one thereof. In still
other embodiments, the first pinned layer 130 may have a structure
including alternately and repeatedly stacked magnetic layers and
non-magnetic layers. The structure including alternately and
repeatedly stacked magnetic layers and non-magnetic layers may be
one of (Co/Pt)n, (CoFe/Pt)n, (CoFe/Pd)n, (Co/Pd)n, (Co/Ni)n,
(CoNi/Pt)n, (CoCr/Pt)n, or (CoCr/Pd)n (where "n" is a natural
number equal to or greater than 2). In some embodiments, the first
pinned layer 130 may further include a cobalt layer or cobalt-rich
layer which is in contact with the first exchange coupling layer
132.
[0049] The first exchange coupling layer 132 may be formed of at
least one of ruthenium, iridium, and rhodium. According to
embodiments of the inventive concepts, the second pinned layer 134
may have a magnetization direction parallel to a thickness
direction of the second pinned layer 134 due to antiferromagnetic
exchange coupling which is induced between the first and second
pinned layers 130 and 134 by the first exchange coupling layer 132.
Thus, the magnetization direction of the second pinned layer 134
may be. The first exchange coupling layer 132 may have a thickness
capable of changing the magnetic direction of the second pinned
layer 134 into a direction anti-parallel to the magnetization
direction of the first pinned layer 130. In some embodiments, the
thickness of the first exchange coupling layer 132 may be in a
range of about 2 .ANG. to about 10 .ANG..
[0050] The second pinned layer 134 may be formed of a magnetic
material having an intrinsic horizontal magnetization property.
Here, the intrinsic horizontal magnetization property means that a
magnetic layer has a magnetization direction parallel to a
longitudinal direction of the magnetic layer when external factors
do not exist. In some embodiments, if a magnetic layer having the
intrinsic horizontal magnetization property is formed on a
substrate, the magnetization direction of the magnetic layer may be
substantially parallel to the top surface of the substrate. In
other words, the second pinned layer 134 may have a magnetization
direction parallel to the widest surface of the second pinned layer
134 when external factors do not exist.
[0051] In some embodiments, the intrinsic horizontal magnetization
property of the second pinned layer 134 may be realized by a
single-layered or multi-layered structure including at least one of
cobalt, iron, and alloys thereof. For example, the second pinned
layer 134 may have a single-layered or multi-layered structure
including at least one of cobalt-iron-boron (CoFeB), cobalt-hafnium
(CoHf), cobalt (Co), and cobalt-zirconium (CoZr). In more detail,
the second pinned layer 134 may have a multi-layered structure
including a cobalt (Co) layer and a cobalt-hafnium (CoHf) layer, or
a multi-layered structure including a cobalt-iron-boron (CoFeB)
layer. These materials are just examples of the material having the
intrinsic horizontal magnetization property of the second pinned
layer 134. However, the inventive concepts are not limited thereto.
In some embodiments, a thickness of the second pinned layer 134 may
be in a range of about 7 .ANG. to about 25 .ANG.. In particular,
the thickness of the second pinned layer 134 may be in a range of
about 10 .ANG. to about 17 .ANG..
[0052] A horizontal magnetization direction of the second pinned
layer 134 having the intrinsic horizontal magnetization property
may be changed into a perpendicular magnetization direction by an
external factor. In some embodiments, the second pinned layer 134
may be in contact with the tunnel barrier TBR. Thus, the second
pinned layer 134 may become a structure having an extrinsic
perpendicular magnetization property by the tunnel barrier TBR.
[0053] In more detail, the second pinned layer 134 may become the
structure having the extrinsic perpendicular magnetization property
(hereinafter, referred to as `an extrinsic perpendicular
structure`) by interface anisotropy caused at a contact interface
of the second pinned layer 134 and the tunnel barrier TBR. If the
tunnel barrier TBR includes magnesium oxide (MgO) and the second
pinned layer 134 include cobalt-iron-boron (CoFeB), the interface
anisotropy may be caused by combination of the oxygen of the tunnel
barrier TBR and the iron (Fe) element of the second pinned layer
134. A non-metal element (e.g., boron (B)) in the second pinned
layer 134 may be exhausted through the interface between the tunnel
barrier TBR and the second pinned layer 134 to accelerate the
combination of the oxygen and the iron.
[0054] The interface anisotropy of the second pinned layer 134 may
be induced by an additional thermal treatment process performed
after the deposition of the second pinned layer 134. In other
words, at least a portion of the second pinned layer 134 may be in
an amorphous state during the deposition process of the second
pinned layer 134, and the second pinned layer 134 may be then
transformed into the extrinsic perpendicular structure by the
thermal treatment process. In this case, a crystal structure of the
second pinned layer 134 may be transformed by influence of a
crystal structure of the tunnel barrier TBR. For example, if the
tunnel barrier TBR has a sodium chloride (NaCl) crystal structure,
the crystal structure of the second pinned layer 134 may be
transformed into a body-centered cubic (BCC) crystal structure
similar to the NaCl crystal structure. In other words, a
<001> crystal plane of the tunnel barrier TBR may be in
contact with a <001> crystal plane of the second pinned layer
TBR to form the interface. The adjustment of the interface crystal
plane of the tunnel barrier TBR and the second pinned layer 134 may
improve a magnetic resistance ratio of the magnetic tunnel
junction.
[0055] Referring to FIG. 8, the first perpendicular magnetic
structure MS1 may include a first free layer 140, a second exchange
coupling layer 142, and a second free layer 144 which are
sequentially stacked between the seed layer 110 and the tunnel
barrier TBR. The first perpendicular magnetic structure MS1
according to the present embodiment may be a multi-layered magnetic
structure including the free layer FRL of the second type magnetic
tunnel junction MTJ2 described with reference to FIG. 3.
[0056] In more detail, the first free layer 140 may be disposed
between the seed layer 110 and the second exchange coupling layer
142, and the second free layer 144 may be disposed between the
second exchange coupling layer 142 and the tunnel barrier TBR. The
second free layer 144 may be formed of a magnetic material having
an intrinsic horizontal magnetization property. In some
embodiments, the intrinsic horizontal magnetization property of the
second free layer 144 may be realized by a singled-layered or
multi-layered structure including at least one of cobalt, iron, and
alloys thereof. For example, the second free layer 144 may have a
single-layered or multi-layered structure including at least one of
cobalt-iron-boron (CoFeB), cobalt-hafnium (CoHf), cobalt (Co), and
cobalt-zirconium (CoZr). In more detail, the second free layer 144
may have a multi-layered structure including a cobalt (Co) layer
and a cobalt-hafnium (CoHf) layer, or a multi-layered structure
including a cobalt-iron-boron (CoFeB) layer.
[0057] A horizontal magnetization direction of the second free
layer 144 having the intrinsic horizontal magnetization property
may be changed into a perpendicular magnetization direction by an
external factor. In some embodiments, the second free layer 144 may
be in contact with the tunnel barrier TBR. Thus, the second free
layer 144 may become a structure having an extrinsic perpendicular
magnetization property (hereinafter, referred to as `an extrinsic
perpendicular structure`) by interface anisotropy caused by the
contact of the tunnel barrier TBR and the second free layer 144.
The second exchange coupling layer 142 may be a non-magnetic metal
layer. For example, the second exchange coupling layer 142 may be
formed of at least one of tantalum, ruthenium, iridium, and
rhodium. The second free layer 144 may be antiferromagnetically
exchange-coupled to the first free layer 140 by the second exchange
coupling layer 142.
[0058] The first free layer 140 may include the same material as
the second free layer 144. For example, the perpendicular magnetic
structure MS1 may include a pair of free layers 140 and 144 formed
of an alloy of cobalt-iron-boron (CoFeB), and the second exchange
coupling layer 142 formed of tantalum between the pair of free
layers 140 and 144.
[0059] In other embodiments, the first free layer 140 may be formed
of a magnetic material having an intrinsic perpendicular
magnetization property. The intrinsic perpendicular magnetization
property may be realized by a single-layered or multi-layered
structure including at least one of perpendicular magnetic
materials including cobalt. In some embodiments, the first free
layer 140 may have a single-layered or multi-layered structure
including a cobalt-platinum alloy, or a cobalt-platinum alloy
including a composition X. The composition X may include at least
one of boron, ruthenium, chrome, tantalum, and an oxide. In other
embodiments, the first free layer 140 may have a multi-layered
structure including cobalt-containing layers and noble metal layers
which are alternately and repeatedly stacked. In this case, the
cobalt-containing layers may be formed of cobalt, cobalt-iron,
cobalt-nickel, or cobalt-chrome, and the noble metal layers may be
formed of platinum or palladium. In still other embodiments, the
first free layer 140 may have a multi-layered structure including
one structure of the some embodiments described above and one
structure of the other embodiments described above.
[0060] Referring again to FIG. 4, the tunnel barrier TBR may
include at least one of magnesium oxide (MgO), titanium oxide
(TiO), aluminum oxide (A10), magnesium-zinc oxide (MgZnO),
magnesium-boron oxide (MgBO), titanium nitride, and vanadium
nitride (VN). In some embodiments, the tunnel barrier TBR may be a
magnesium oxide (MgO) layer. Alternatively, the tunnel barrier TBR
may include a plurality of layers.
[0061] FIGS. 9 and 10 are cross-sectional views illustrating
examples of a second perpendicular magnetic structure constituting
a portion of a magnetic tunnel junction according to embodiments of
the inventive concepts. Referring to FIG. 9, the second
perpendicular magnetic structure MS2 may include a first free layer
140, a second exchange coupling layer 142, and a second free layer
144 which are disposed between the tunnel barrier TBR and the
capping layer 112. The second perpendicular magnetic structure MS2
according to the present embodiment may be a multi-layered magnetic
structure including the free layer FRL of the first type magnetic
tunnel junction MTJ1 described with reference to FIG. 2.
[0062] In more detail, the first free layer 140 may be disposed
between the capping layer 112 and the second exchange coupling
layer 142, and the second free layer 144 may be disposed between
the tunnel barrier TBR and the second exchange coupling layer 142.
The first free layer 140 may be antiferromagnetically
exchange-coupled to the second free layer 144 by the second
exchange coupling layer 142. Other features of the first and second
free layers 140 and 144 except their positions in the present
embodiment may be the same as corresponding features of the first
and second free layers 140 and 144 described with reference to FIG.
8. Thus, the detail descriptions thereto are omitted.
[0063] Referring to FIG. 10, the perpendicular magnetic structure
MS2 may include a first pinned layer 130, a first exchange coupling
layer 132, and a second pinned layer 134 which are disposed between
the tunnel barrier TBR and the capping layer 112. The perpendicular
magnetic structure MS2 according to the present embodiment may be a
multi-layered magnetic structure including the pinned layer PNL of
the second type magnetic tunnel junction MTJ2 described with
reference to FIG. 3.
[0064] In some embodiments, the first pinned layer 130 may be
disposed between the capping layer 112 and the first exchange
coupling layer 132, and the second pinned layer 134 may be disposed
between the tunnel barrier TBR and the first exchange coupling
layer 132. The first pinned layer 130 may be antiferromagnetically
exchange-coupled to the second pinned layer 134 by the first
exchange coupling layer 132. Other features of the first and second
pinned layers 130 and 134 except their positions in the present
embodiment may be the same as corresponding features of the first
and second pinned layers 130 and 134 described with reference to
FIG. 7. Thus, the detail descriptions thereto are omitted.
[0065] Referring again to FIG. 4, the capping layer 112 may include
at least one of tantalum (Ta), aluminum (Al), copper (Cu), gold
(Au), silver (Ag), titanium (Ti), tantalum nitride (TaN), and
titanium nitride (TiN). The second electrode 114 may include a
conductive material. For example, the second electrode 114 may
include a conductive metal nitride such as titanium nitride and/or
tantalum nitride.
[0066] A second dielectric layer 120 may be disposed on an entire
top surface of the substrate 100 to cover the first conductive
structure CS1, the magnetic tunnel junction MTJ, and a second
conductive structure CS2. The upper contact plug 116 may penetrate
the second dielectric layer 120 so as to be connected to the second
electrode 114. The second insulating layer 120 may include at least
one of an oxide, a nitride, and an oxynitride. The upper contact
plug 116 may include at least one of a metal (e.g., titanium,
tantalum, copper, aluminum, or tungsten) and a conductive metal
nitride (e.g., titanium nitride or tantalum nitride). An
interconnection 118 may be disposed on the second dielectric layer
120. The interconnection 118 may be connected to the upper contact
plug 116. The interconnection 118 may include at least one of a
metal (e.g., titanium, tantalum, copper, aluminum, or tungsten) and
a conductive metal nitride (e.g., titanium nitride or tantalum
nitride). In some embodiments, the interconnection 118 may be a bit
line.
[0067] FIG. 5 is a cross-sectional view illustrating a magnetic
memory device according to other embodiments of the inventive
concepts. In the present embodiment, the same components as
described in the aforementioned embodiment of FIG. 4 will be
described by the same reference numerals or the same reference
designators. The descriptions to the same components will be
omitted or mentioned briefly for the purpose of ease and
convenience in explanation. Referring to FIG. 5, a first conductive
structure CS1, a magnetic tunnel junction MTJ, and a second
conductive structure CS2 may be sequentially stacked on the first
dielectric layer 102. The first conductive structure CS1 may be
electrically connected to the top surface of the lower contact plug
104. The first conductive structure CS1, the magnetic tunnel
junction MTJ, and the second conductive structure CS2 may have
sidewalls aligned with each other.
[0068] The first conductive structure CS1 may include a first
electrode 106 on the first dielectric layer 102 and a seed layer
110 on the first electrode 106. The magnetic tunnel junction MTJ
may include a first perpendicular magnetic structure MS1 on the
seed layer 110, a second perpendicular magnetic structure MS2 on
the first perpendicular magnetic structure MS1, and a tunnel
barrier TBR between the first and second perpendicular magnetic
structures MS1 and MS2. In more detail, the first perpendicular
magnetic structure MS1 may be disposed between the seed layer 110
and the tunnel barrier TBR, and the second perpendicular magnetic
structure MS2 may be disposed between the tunnel barrier TBR and
the second conductive structure CS2. The second conductive
structure CS2 may include a second electrode 114 on the second
perpendicular magnetic structure MS2, a capping layer 112 between
the second perpendicular magnetic structure MS2 and the second
electrode 114, and a blocking layer 108 between the second
electrode 114 and the capping layer 112.
[0069] The blocking layer 108 may include an amorphous metal
compound. The blocking layer 108 may be in an amorphous state when
deposited. The blocking layer 108 may not be crystallized by an
annealing process performed after the deposition thereof. In other
words, the amorphous state of the blocking layer 108 may be
maintained after the annealing process. The blocking layer 108 of
FIG. 5 is the same as the blocking layer 108 included in the
magnetic memory device described with reference to FIG. 4.
[0070] Generally, the second electrode 114 may have a predetermined
crystal structure and may be in contact with the capping layer 112.
A crystal structure of the second electrode 114 may be transferred
to the capping layer 112 and the magnetic tunnel junction MTJ by an
annealing process performed after the second electrode 114 is
deposited. Thus, the crystal structure of the second electrode 114
may influence a crystal structure and orientation of the magnetic
tunnel junction MTJ. As a result, a tunnel magnetic resistance
(TMR) characteristic of the magnetic tunnel junction MTJ may be
deteriorated. Additionally, an exchange coupling characteristic
between magnetic layers constituting the magnetic tunnel junction
MTJ may also be deteriorated.
[0071] According to embodiments of the inventive concepts, the
blocking layer 108 including the amorphous metal compound may not
be crystallized by the annealing process performed after the
deposition of the second electrode 114 such that the amorphous
state of the blocking layer 108 may be maintained after the
annealing process. Since the blocking layer 108 is disposed between
the second electrode 114 and the capping layer 112, it is possible
to prevent the crystal structure of the second electrode 114 from
influencing the crystal structure and orientation of the magnetic
tunnel junction MTJ through the capping layer 112 by the annealing
process. As a result, the TRM characteristic of the magnetic tunnel
junction MTJ may be improved. Additionally, the exchange coupling
characteristic between the magnetic layers of the magnetic tunnel
junction MTJ may also be improved.
[0072] FIG. 6 is a cross-sectional view illustrating a magnetic
memory device according to still other embodiments of the inventive
concepts. In the present embodiment, the same components as
described in the aforementioned embodiments of FIGS. 4 and 5 will
be described by the same reference numerals or the same reference
designators. The descriptions to the same components will be
omitted or mentioned briefly for the purpose of ease and
convenience in explanation. Referring to FIG. 6, a first conductive
structure CS1, a magnetic tunnel junction MTJ, and a second
conductive structure CS2 may be sequentially stacked on the first
dielectric layer 102. The first conductive structure CS1 may
include a first electrode 106 on the first dielectric layer 102, a
seed layer 110 on the first electrode 106, and a first blocking
layer 108a between the first electrode 106 and the seed layer 110.
The magnetic tunnel junction MTJ may include a first perpendicular
magnetic structure MS1 on the seed layer 110, a second
perpendicular magnetic structure MS2 on the first perpendicular
magnetic structure MS1, and a tunnel barrier TBR between the first
and second perpendicular magnetic structures MS1 and MS2. In more
detail, the first perpendicular magnetic structure MS1 may be
disposed between the seed layer 110 and the tunnel barrier TBR, and
the second perpendicular magnetic structure MS2 may be disposed
between the tunnel barrier TBR and the second conductive structure
CS2. The second conductive structure CS2 may include a second
electrode 114 on the second perpendicular magnetic structure MS2, a
capping layer 112 between the second perpendicular magnetic
structure MS2 and the second electrode 114, and a second blocking
layer 108b between the second electrode 114 and the capping layer
112.
[0073] Each of the first and second blocking layers 108a and 108b
may include an amorphous metal compound. Each of the first and
second blocking layers 108a and 108b may be in an amorphous state
when deposited. Each of the first and second blocking layers 108a
and 108b may not be crystallized by an annealing process performed
after the deposition thereof. In other words, the amorphous state
of each of the first and second blocking layers 108a and 108b may
be maintained after the annealing process. Each of the first and
second blocking layers 108a and 108b is the same as the blocking
layer 108 included in the magnetic memory device described with
reference to FIG. 4. The first blocking layer 108a may have a top
surface U1a planarized by a planarization process performed after
the deposition of the first blocking layer 108a and before the
deposition of the seed layer 110.
[0074] According to embodiments of the inventive concepts, the
blocking layer including the amorphous metal compound may not be
crystallized but may be maintained in the amorphous state after the
annealing process performed after deposition of the magnetic tunnel
junction MTJ. If the blocking layer is disposed between the first
electrode 106 and the seed layer 110, it is possible to prevent the
crystal structure of the first electrode 106 from influencing the
crystal structure and orientation of the magnetic tunnel junction
MTJ through the seed layer 110 by the annealing process performed
after the deposition of the magnetic tunnel junction MTJ.
Additionally, if the blocking layer is disposed between the second
electrode 114 and the capping layer 112, it is possible to prevent
the crystal structure of the second electrode 114 from influencing
the crystal structure and orientation of the magnetic tunnel
junction MTJ through the capping layer 112 by the annealing process
performed after the deposition of the second electrode 114. In
other words, since the blocking layer prevents the crystal
structures of the first and second electrodes 106 and 114 from
influencing the crystal structure and orientation of the magnetic
tunnel junction MTJ, the TRM characteristic and the exchange
coupling characteristic of the magnetic tunnel junction MTJ may be
improved. As a result, the magnetic memory devices having excellent
reliability may be realized.
[0075] FIGS. 11 and 12 are schematic block diagrams illustrating
electronic devices including magnetic memory devices according to
embodiments of the inventive concepts. Referring to FIG. 11, an
electronic device 1300 including the semiconductor device according
to the inventive concepts may be one of a personal digital
assistant (PDA), a laptop computer, a portable computer, a web
tablet, a wireless phone, a mobile phone, a digital music player, a
cable/wireless electronic device, or any composite electronic
device including at least two thereof. The electronic device 1300
may include a controller 1310, an input/output (I/O) unit 1320
(e.g., a keypad, a keyboard, or a display), a memory device 1330,
and a wireless interface unit 1340 which are coupled to each other
through a data bus 1350. For example, the controller 1310 may
include at least one of a microprocessor, a digital signal
processor, a microcontroller, or another logic device having a
similar function to any one thereof. The memory device 1330 may
store, for example, commands executed through the controller 1310.
Additionally, the memory device 1330 may store user's data. The
memory device 1330 may include at least one of the semiconductor
devices (i.e., the magnetic memory devices) in the aforementioned
embodiments of the inventive concepts. The electronic device 1300
may use the wireless interface unit 1340 in order to transmit data
to a wireless communication network communicating with a radio
frequency (RF) signal or in order to receive data from the network.
For example, the wireless interface unit 1340 may include antenna
or a wireless transceiver. The electronic device 1300 may be used
in order to realize a communication interface protocol of a
communication system such as CDMA, GSM, NADC, E-TDMA, WCDMA,
CDMA2000, Wi-Fi, Muni Wi-Fi, Bluetooth, DECT, Wireless USB,
Flash-OFDM, IEEE 802.20, GPRS, iBurst, WiBro, WiMAX,
WiMAX-Advanced, UMTS-TDD, HSPA, EVDO, LTE-Advanced, or MMDS.
[0076] Referring to FIG. 12, the semiconductor devices according to
embodiments of the inventive concepts may be used in order to
realize memory systems. A memory system 1400 may include a memory
device 1410 and a memory controller 1420 for storing massive data.
The memory controller 1420 may control the memory device 1410 in
order to read/write data from/into the memory device 1410 in
response to read/write request of a host 1430. The memory
controller 1420 may make an address mapping table for mapping an
address provided from the host 1430 (e.g., a mobile device or a
computer system) into a physical address of the memory device 1410.
The memory device 1410 may include at least one of the
semiconductor devices (i.e., the magnetic memory devices) according
to the above embodiments of the inventive concepts.
[0077] The semiconductor devices (i.e., the magnetic memory
devices) described above may be encapsulated using various
packaging techniques. For example, the semiconductor devices
according to the aforementioned embodiments may be encapsulated
using any one of a package on package (POP) technique, a ball grid
arrays (BGAs) technique, a chip scale packages (CSPs) technique, a
plastic leaded chip carrier (PLCC) technique, a plastic dual
in-line package (PDIP) technique, a die in waffle pack technique, a
die in wafer form technique, a chip on board (COB) technique, a
ceramic dual in-line package (CERDIP) technique, a plastic metric
quad flat package (PMQFP) technique, a plastic quad flat package
(PQFP) technique, a small outline package (SOC) technique, a shrink
small outline package (SSOP) technique, a thin small outline
package (TSOP) technique, a thin quad flat package (TQFP)
technique, a system in package (SIP) technique, a multi-chip
package (MCP) technique, a wafer-level fabricated package (WFP)
technique and a wafer-level processed stack package (WSP)
technique. The package in which the semiconductor memory device
according to one of the above embodiments is mounted may further
include at least one semiconductor device (e.g., a controller
and/or a logic device) that controls the semiconductor memory
device.
[0078] According to embodiments of the inventive concepts, the
blocking layer including the amorphous metal compound may be
disposed between the magnetic tunnel junction and the electrode.
The blocking layer may prevent the crystal structure of the
electrode from influencing the crystal structure and orientation of
the magnetic tunnel junction. Thus, the TMR and exchange coupling
characteristics of the magnetic tunnel junction may be improved. As
a result, the magnetic memory devices having excellent reliability
may be realized.
[0079] While the inventive concepts have been described with
reference to example embodiments, it will be apparent to those
skilled in the art that various changes and modifications may be
made without departing from the spirits and scopes of the inventive
concepts. Therefore, it should be understood that the above
embodiments are not limiting, but illustrative. Thus, the scopes of
the inventive concepts are to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing description.
* * * * *